1. Field of the Invention
The present invention relates to a method and apparatus for loading a pre-molded film into a mold. More specifically, the invention relates to a method and apparatus that enables the high speed loading and unloading of large automotive size components into an injection molding machine.
2. Description of the Related Arts
In-mold mold film laminates have been manufactured using movable molds and stationary cores as illustrated in U.S. Pat. No. 3,668,034('034). The '034 patent teaches placing a decorative laminate within a mold and then injection molding a polymeric material behind the laminate. The polymeric material heats, softens and finally fuses to the backing on the laminate.
The finished article includes a rigid substrate of a polymeric material and an exterior surface that displays the decorative laminate. Heretofore, methods for manufacturing molded articles having this type of decorative surface have required hand placement of the laminate within the tool prior to molding. Hand placement requires that the operator have direct access to the molding surfaces. These surfaces are not always accessible, especially when molding larger parts as commonly used in the automotive industry. It is desirable to automate the process by providing an apparatus that automatically loads the film into the mold press. A difficulty arises when attempting to automate the process of transferring the film into the mold because the film is flexible and may be damage by folding or scuffing in robotic equipment that manipulates the film.
Earlier automation relating to film handling usually involves handling the film prior to its thermoforming. The film handling occurs when the film is still in a sheet form. The flat sheets are easily manipulated by the film handling equipment. A problem arises in handling this film after it has been thermoformed into the shape of the finished article. The film displays a highly contour shape with three-dimensional surfaces that generally lack attachment points for film handling equipment. Further, it is necessary to handle the film by the decorative surface. The decorative surface is easily damaged because it is not rigid or self-supporting.
If the film is not properly transferred to the molding press, it may be either damaged or display a wrinkled appearance after molding. Properly positioning the film in the mold has been a significant impediment to the wide spread use of film transfers in large-molding applications. Conventional mold presses are encapsulated in closed off areas and are not accessible to the equipment operator. These presses require that a robotically controlled arm remove the article. It is desirable that the robotically controlled arm normally used to remove the molded articles from a mold be modified to include a mechanism that enables the arm to transfer a pre-molded film into a mold. It is further desirable that the robotically controlled arm accept the film for transfer into a mold and dispense the finish molded articles to the same location so that one equipment operator may both supply the molding press with pre-molded film and remove finished molded articles. It is a further desirable that the cycle time for manufacturing a film-coated article be approximately the same cycle time of manufacturing an article without a film coating.
These deficiencies and problems are overcome by the present invention.